Tamperproof carton



June 5, 1 D. B. ANDREWS ET AL 3,037,684

TAMPERPROOF CARTON Filed Sept. 8, 1960 2 Sheets-Sheet 1 '7 4.5 45 j 4 o 4547a 46 I8 a oas '36? 1% {38 l I I l 1e 40 \4\0b 40a 4 l5 f as H /I2 26 A g e United States Patent f 3,037,684 TAMPERPROOF CARTON David B. Andrews, Neenah, and George L. Meyers, Menasha, Wis, assignors to American Can Company, New York, N.Y., a corporation of New Jersey Filed Sept. 8, 1960, Ser. No. 54,720 11 Claims. (Cl. 229-45) This invention relates to a tamperproof, edge locking carton which may be made from a single blank, of a type suitable for a variety of uses such as the packaging of food products. More specifically, the invention may with particular advantage be used as a carton for packaging frozen foods such as pies.

Further details and advantages of the invention will be apparent from the following specification and appending drawings wherein:

FIGURE 1 is a plan view of a single blank suitably cut and scored to form a carton having edge locking,

FIGURE 1A is an enlarged fragmental view of the portion of the blank enclosed by a dotted line in FIGURE 1 and shows the female locking slits forming a part of the invention,

FIGURE 1B is an enlarged fragmental view of another type of female locking slit forming a part of the invention,

FIGURE 2 is a perspective view, partially cut QIWEY, of the blank of FIGURE 1 partially set up and glued to form a carton shell,

FIGURE 3 is an enlarged, perspective view, similar to FIGURE 2, showing a further stage in forming the completed carton,

FIGURE 4 is a frag-mental end view of the closed carton,

FIGURE 5 is a fragmental top view of the closed carton,

FIGURE 6 is a fragrnental, sectional side view of the closed carton taken along 66 of FIGURE 4,

FIGURE 7 is an enlarged fragmental, perspective inside view of the closed carton showing the male locking tab in position, and

FIGURE 8 is a perspective view of the closed carton.

Referring first to FIGURE 1, the carton is'made of a single foldable blank A of flexible material such as paperboard. The completed carton is shown in FIGURE 8. The blank A is divided by score lines 10-16 and cut lines 17-18 into hingedly connected panels and flaps, including main panels 25 and 26, side panels 27 and 28, glue flap 29, dust flaps 30 and end closure flaps 321. End closure flaps 32 are hingedly connected to opposite ends of panel 26 by fragmental score lines 35-38, between the interrupted portions of which are positioned cut lines 40 which form female locking elements. Cut lines 40 include a central segment 40a parallel to scores and terminal segments 40b extending at an angle from the ends of the central portion.

Projecting from the end closure flaps 31 are male locking tabs 45 which are hinged to flaps 31 along score lines 46. The lateral portions of tabs 45 are separated from flaps 31 by cut lines 47 which terminate in inwardly directed out line terminal portions47a. Flap 29 bears an adhesive by which it may be adhered to the interior of side panel 27 to form the carton shell depicted in FIG- URE 2.

, FIGURE 1A is a fragmental view of a portion of the alternate scoring 3538 and out line 40 of FIGURE 1. Cuts 40 'are positioned in relation to the scoring 35-38 so that central out segments 46a be somewhat outside score lines 35-38 and terminal cut segments 40b extend inwardly at an angle through or beyond said scoring 3538 to terminate somewhat inwardly of scores 35--38.

FIGURE 1B is a fragmental view of a portion of the 3,037,684 Patented June 5, 1962 alternate scoring -138 and cut line which is anform of female locking slit. Cut 140 is positioned in relation to the scoring 136, 137 so that the central cut segment 140a is outside score lines 136, 137 and terminal cut segments 14012 extend inwardly through or beyond score lines 136, 137. Central segment 140:: provides an upstanding portion when flap 132 is folded inwardly.

In FIGURE 2 the carton is partially set up with glue flap 29 adhered to and underlying side panel 27. In forming the completed carton, one end of the carton is closed by first infolding one pair of dust flaps 30 and then infolding the adjacent closure flap 32, as seen in FIGURE 3. Male locking tabs 45 are then folded inwardly as shown in FIGURE 3 prior to insertion thereof into the female locking slits 40. When folded inwardly tabs 45 lie inwardly from the outer edge of closure flaps 31 with the distance from the tabs to main panel 25 being less than the distance between the main panels when the completed carton is closed. An alternate procedure would be to first infold adjacent closure flap 32 and then infold one pair of dust fiaps 30. Male locking tabs 45 are then folded inwardly as before. This procedure insures that the edges, defined by cut lines 17 18, of dust flaps 30 lie parallel and adjacent to score lines "15 so as to provide anti-racking action.

FIGURES 4, 5, 6 and 7 show fragmentary views of the closed carton. In FIGURE 4 male locking tab 45 has been inserted into the female locking slit 40 which was exposed by the folding in the inner end panel 32. The total length of cut or female locking slit 40 taken along a line passing through the ends of the cut or slit is essentially equal to the lateral dimension of cooperating male tab 45, to facilitate locking engagement. It will be clear from FIGURES 3, 6 and 8 that the configuration of slit 40 provides an upstanding portion 26a of panel 26 which readily engages tab 45 to insure initial entry of tab 45 into the female locking element. The lateral portions of the male locking tab 45, which extend under end panel 32 when locking engagement is accomplished, are identified in FIGURE 4 et seq. as 45a. It will also be seen that terminal cuts 47a provide an extension or throat portion 45b which gives a length to male element or tab 45 sufficient to insure locking engagement of pertions 45a beneath flap 32. When the end closure flap 32 is folded inwardly, the configuration of terminal cut segments 40b lying partly in end closure flap 32 and partly in panel 26 is such that portions 45a are guided up under closure flap 32 in locking engagement. The extensions 45a of tab 45 prevent the removal of the tab once the carton has been closed. When folded,

as shown in FIGURE 3, terminal cuts 47a also provide a set back of tabs 45 from the edge 31a of the outer end panel 31, and when inserted in the slit 40, portions 45a consequently pull back under the ends of inner end panel 32. The edges 45a of the male locking tab 45 are held in place by the pressure thereon of panel 26 exerted at the female slit 40. The removal of the locking tabs from the slits therefore requires a mutilation of the carton, which is therefore tamperproof, since any previous opening of the carton will be evident.

As shown in sectional view in FIGURE 6 the folding of outer end panel 31 over inner end panel 32 gives reinforcement to the end of the carton when set up. The locking means employed maintains panel 31 on panel 32 in close relationship to prevent bulging and to preserve the shape of the carton as initially set up.

The present invention provides a carton construction which requires a minimum amount of paperboard stock. The carton can be readily set up, filled with the commodity to be packaged, and locked by automatic machinery. The carton is tamperproof and maintains its initial shape without bending or bulging. Although exemplified with a plurality of locking elements, it is under stood that the carton may have one or more depending upon the desired size and shape of the completed carton.

We claim:

1. A tamperproof carton formed of a single blank suitably cut and scored comprising a pair of opposed main panels, opposed side panels hingedly connected to said main panels, a pair of end closure flaps hingedly connected to adjacent ends of said main panels; a plurality of female locking slits adjacent the hinge connection of one of said closure flaps to one main panel, each of said slits being a continuous shaped cut line comprising a central segment in said one closure flap closely adjacent to said hinge connection and at the ends of said central segment, terminal segments tapering towards and through said hinge connection into the adjacent main panel, said slits having a bowed shape and forming a receptive opening when said one closure flap is folded inwardly; said carton having a plurality of male looking tabs, correspending in number to the said female locking slits, extending outwardly from the edge of the other of said closure flaps opposite the hinge connection of said other flap to the other main panel, said tabs being of width approximately equal to the length of said slits taken along a line passing through the ends of said slits, each tab having a centered throat portion, said throat portion being hingedly connected to said other closure flap by a score line positioned inwardly of the outer edge of said other flap at a distance from said other main panel which is less than the distance between said main panels in the closed carton, said tabs being engaged in said slits when said carton is closed with the lateral portions thereof extending laterally beyond the throat portions at each side thereof and extending under adjacent portions of said one closure flap in permanent locked relationship therewith, said locking relationship being maintained by pressure contact of said one main panel against said tabs to maintain them under the one said closure flap.

2. The carton of claim 1 wherein the slit is of arcual shape.

3. The carton of claim 1 wherein the central segment in said closure flap is parallel to said hinge connection and the terminal segments are straight lines.

4. The carton of claim 2 wherein the centered throat portion of each male looking tab is approximately equal in width to the length along said hinge connection of the portion of said slit lying in said one closure flap.

5. The carton of claim 3 wherein the centered throat portion of each male locking tab is approximately equal in Width to said central segment.

6. A tamperproof carton formed of a single blank suitably cut and scored comprising a pair of opposed main panels, opposed side panels hingedly connected to said main panels, a pair of end closure flaps hingedly connected to adjacent ends of said main panels; a female locking slit adjacent the hinge connection of one said closure flap to one main panel, said slit being a continuous shaped out line comprising a central segment in said one closure flap closely adjacent to said hinge connection and at the ends of said central segment, terminal segments tapering toward and through said hinge connection into the adjacent main panel, said slit having a bowed shape forming a receptive opening and providing an extending portion from said main panel when said one closure flap is folded inwardly; said carton having a male locking tab extending outwardly from the edge of said other flap opposite the hinge connection of said other flap to the other main panel, said tab being of width approximately equal to the length of said slit taken along a line passing through the ends of said slit, said tab having a centered throat portion, said throat portion being hingedly connected to said other closure flap by a score line positioned inwardly of the outer edge of said other flap so that when folded inwardly the tab lies inwardly of the outer edge thereof, said tab being guided into engagement in said slit by said portion extending from said one main panel when said carton is closed with the lateral portions of the tab extending laterally beyond the throat portion at each side thereof and extending under adjacent portions of said one closure flap in permanent locked relationship therewith, said locking relationship being maintained by the pressure contact of said one main panel against said tab and by said tab being positioned at a distance from said other main panel which is less than the distance between the main panels in the closed carton so as to exert a pulling action when said tab is engaged in said slit.

7. The carton of claim 6 wherein the central segment in said closure flap is parallel to said hinge connection and the terminal segments are straight lines.

8. The carton of claim 6 wherein the slit is of arcual shape.

9. The carton of claim 7 wherein the centered throat portion of the male locking tab is approximately equal in width to said central segment.

10. The carton of claim 8 wherein the centered throat portion of the male locking tab is approximately equal in width to the length along said hinge connection of the portion of said slit lying in said one closure flap;

11. A locking means for a carton, said carton having two panels located at a substantial angle to each other and having adjacent edges, the first of said panels having a closure flap hingedly connected thereto along the edge adjacent the other of said panels; said means comprising a female locking slit adjacent the hinge connection of the closure flap to said first panel, said slit being a continuous shaped out line comprising a central segment in said closure flap closely adjacent to said hinge connection and at the ends of said central segment terminal segments tapering toward and through said hinge connection into the adjacent said first panel, said slit having a bowed shape forming a receptive opening and providing an extending portion from said first panel when said closure flap is folded inwardly, and a male looking tab extending outwardly from said adjacent edge of the other panel, said tab being of width approximately equal to the length of said slit taken along a. line passing through the ends of said slit, said tab having a narrowed centered throat portion by which is hingedly joined to said other panel, said tab being guidable by said extending portion into locking engagement within said slit with lateral portions of the tab extending under adjacent portions of said closure flap in locked relationship therewith, said locking relationship being maintained by the pressure contact of saidfirst panel against said tab to maintain it under said closure flap.

References Cited in the file of this patent UNITED STATES PATENTS 2,190,433 Palmer Feb. 13, 1940 2,320,665 Shearer June 1,1943 2,481,288 Cage Sept. 6, 1949 2,658,660 Keller Nov. 10', 1953 2,690,286 Dawson Sept. 28, 1954 2,690,290 Turner Sept. 28, 1954 2,731,191 Layne Ian. 17, 1956 2,885,140 Guyer May 5, 1959 2,944,717 Lynch July 12, 1960 Disclaimer 3,037,684.-Da'vid B. Andrews, N eenah, and George L. Me

gem, Menasha, Wis,

AMPERPROOF CARTON. Patent dated June 5, 1962. Disclaimer filed June 17, 1963, by the assignee, Amem'can Own 0 ny. Hereb enters this disclaimer to claims 1 to 11, inclusive, of said patent.

Gazette September 10,1963] 

